Use of morphology inspection methodology in the myocardial tissue samples / 解剖学报

Objective: To investigate the use of morphology inspection methods in myocardial diseases, and to evaluate their advantages and disadvantages. Methods: Myocardial tissues were staining by phosphotungstic aci hematoxylin(PTAH), Masson, elastic fiber tissue (ET) + Van Gienson(VG), Congo red, Schiff periodic acid shiff(PAS), and Cram staining methods. Immunehistochemical method, and transmission microscopy had also been applied to study the myocardial tissue. Results: HE staining differentiation of myocardial tissue was not well; Masson trichromatic staining differentiation of myocardial cells and collagen fibers had clear distinction; ET + VG staining method was able to distinguish among elastic fibers, collagen fibers, fibers and amyloid; Congo red stain was mainly used in the detection of amyloidosis, the PAS reaction assisted in the diagnosis of glycogen storage disease. Immunohistochemical technology was an useful tool in disease model study and diagnosis of the cardiac disease. Electron microscopic observation of the ultrastructure was an important means of etiological diagnosis. Conclusion: For myocardial tissue samples, a combination of morphology methods of the histology, subcellular and molecular can get a better observation.

Structure of xanthan gum and cell ultrastructure at different times of alkali stress

Abstract The effect of alkali stress on the yield, viscosity, gum structure, and cell ultrastructure of xanthan gum was evaluated at the end of fermentation process of xanthan production by Xanthomonas campestris pv. manihotis 280-95. Although greater xanthan production was observed after a 24 h-alkali stress process, a lower viscosity was observed when compared to the alkali stress-free gum, regardless of the alkali stress time. However, this outcome is not conclusive as further studies on gum purification are required to remove excess sodium, verify the efficiency loss and the consequent increase in the polymer viscosity. Alkali stress altered the structure of xanthan gum from a polygon-like shape to a star-like form. At the end of the fermentation, early structural changes in the bacterium were observed. After alkali stress, marked structural differences were observed in the cells. A more vacuolated cytoplasm and discontinuities in the membrane cells evidenced the cell lysis. Xanthan was observed in the form of concentric circles instead of agglomerates as observed prior to the alkali stress.